SPRITES 99 YUCCA RIDGE FIELD STATION
FMA Research
JD 99219- 07 AUGUST 1999
PRELIMINARY SPRITE LOG
The following is a very preliminary listing of the times of sprites imaged at the
Yucca Ridge Field Station. These are based solely on real-time visual inspection of
the video monitoring system. There are most likely some additional sprites not listed
and not all those below may in fact be sprites. All times are UTC. Times are likely
to be within ±5 seconds of actual time.
SUMMARY:A weak low finally moved east and brought in drier, warmer air to the
Front Range ending the long upslope regime. Viewing was good at YRFS, Jelm and Custer
(early). Extremely sharp star field, and no moon. Little evidence of forest fire smoke.
Daytime convection was muted and a few weak storms moved out into Plains. Old MCS in
Nebraska moved into Iowa, causing a morning cancellation of the balloon mission. The
western end of system remained convectively active as it stayed nearly stationary around
Omaha. Tohoku monitored that system after 0500, and it made three elves, the first at
0609.23 UTC. Gene Wescott reported UofA saw six sprites with this system, which had less
than 10% positives. Another small MCS developed northwest of Rapid City and moved ESE
during the evening. It averaged 5-10% positive and had modest flash rates (500-900/hr)
from 0300-0600 before starting to collapse. There was some stratiform radar echo but
really not much larger than 10**4 km**2. This system was right on edge of spriting, but
90 minutes of monitoring with the patrol Xybion camera revealed no events. Tohoku
continued to watch the eastern NE storm after 0630. The MM5 model ran using 18 hours
of eta data. The run was completed successfully.
(S) = Sprite; (E) = Elve; (B) = Blue Jet; (CF/CG) = Cloud/Ground flash; (M)=Meteor
JD 99219 07 AUGUST 1999
0510.Start LLTV Observations; a number of bright meteors were noted
0609.23.66 [E]
0610.25.72 [E]
0623.01.55 [E]
UofAk reports six sprites with this system
0630 End LLTV Observations